Ferroelectric materials can form the basis for data storage wherein binary “1” and “0” levels are represented by the electric polarization of a ferroelectric film pointing “up” or “down”. A data storage device that utilizes, for example, a ferroelectric storage medium can include an electrode, which also may be referred to as a “tip” or “probe tip”, that is movable relative to the storage medium. The storage medium may include a substrate, an electrode layer and a ferroelectric storage layer. In both cases the binary “1” and “0” are stored by causing the polarization of the ferroelectric film to point “up” or “down” in a spatially small region or domain local to the electrode. Data can then be read out destructively by applying a voltage of a magnitude and polarity such as to cause the polarization to point “up”. The domains polarized “down” (e.g. representing “0”), will then switch to the “up” state, and a charge will flow which is proportional to the remnant polarization of the ferroelectric. Domains polarized “up” will have no such current flow. The presence or absence of this current flow, as determined by a sense amplifier, can then be used to determine whether the domain had contained a “1” or “0”.
Data storage devices are being proposed to provide smaller size, higher capacity, and lower cost data storage devices. Data storage devices usually store one bit at one location of the device. In order to increase the capacity of the device, it is necessary to decrease the bit size. However, there are several technological and fundamental limitations to overcome to decrease the bit size such as, for example, amplification of readout signal and stability of the bits.